Indenfor Læderhuden ere de to Muskellag, nemlig 
-'Tvermusklerne og Længdemusklerne. "'Tvermusklerne, der 
ere bundne til den indre Flade af Corium, danne nesten 
en sammenhængende Hud, kun skilte fra hverandre ved en 
yderst fin Bindevævsstribe, hvori findes smaa Kalkkorn. 
Henimod Dyrets bagerste Ende blive Tvermusklerne noget 
stærkere og danne her en Sphincter omkring Analaabningen. 
I den forreste Ende hjælpe de til at danne Sphincteren om 
Munden. . Hvorvidt disse Tvermuskler gaa uafbrudt rundt 
Legemets indre Hudflade og saaledes danne virkelige Ring- 
muskler, eller de ere afbrudte ved Længdemusklerne, skulle 
vi ikke med Sikkerhed kunne afgjøre, da vi ikke have havt 
Materiale nok til en saadan Undersøgelse, der forøvrigt 
frembyder adskillige Vanskeligheder; men efter hvad vi 
have seet, tro vi helst, at de virkelig ere afbrudte 1 Lig- 
hed med, hvad vi anførte ved at omtale Tyermusklerne hos 
Trochostoma*. 
Længdemusklerne ere 5, hvoraf 2 paa Ryg- og 3 paa 
Bugfladen. De strække sig fra Munden til Analaabningen, 
ere enkelte, temmelig tykke, omtrent 0.8”” brede, og bin- 
des foruden til Corium ogsaa til Tvermusklerne med en 
Mengde stærke Bindevævstraade, Fig. 3, a. Paa Dyrets 
bagerste Ende blive de noget smalere, og paa den forreste, 
hvor de ligeledes smalne af, gaa de over paa Mundskivens 
Underflade og fæste sig i Nærheden af Munden. Muskel- 
laget er beklædt med Bughinden (Peritoneum). der dannes 
af Bindevæv, hvori findes enkelte Muskelfibre, yderst smaa, 
spredte, aflange Kalkkorn, og paa hvis indre Flade er et 
flimrende Epithelovertræk. 
I Kroppens Hud findes Kalklegemer, der optræde 
under to Hovedformer, nemlig som Stave (Spikler) og som 
elliptiske Skiver. Spiklerne ere temmelig spredte og kun 
paa enkelte Steder, saasom henimod Fødderne, mere sam- 
lede. De ere meget smaa, fra 0.054—0.080”” lange, og 
fra 0.002—0.003”” brede, have hyppigst en krummet Form, 
noget nærmende sig Hesteskoens, Fig. 5, 5, 5, medens 
enkelte ere næsten lige, Fig. 4, 6,6. De have paa Midten 
en Knude, og mod begge Ender ere |de tildels forsynede 
med fine Takker, Fig. 5, 6, 7, kun yderst sjelden ere de 
forgrenede, Fig. 8. Det er især i det ydre Lag af Læder- 
huden, at disse Spikler ere leirede, dog hænder det. at 
man ogsaa træffer enkelte i det indre Lag. 
De elliptiske Kalklegemer findes væsentligst i det 
indre Lag; men dog støder man paa dem imellem Kalk- 
spiklerne 1 det ydre Lag. De ere flade, bestaa af en peri- 
pherisk Del, som er bredest og ufarvet. og et Centrum, der 
‘ Magazin for Naturvid. 24 B., pag. 232. Christiania 1878. 
22 
_ transverse 
Underneath the corium are the two muscular layers, 
consisting of transverse and longitudinal muscles. The 
muscles, which are attached to the inner 
surface of the corium, constitute an almost continuous 
integument, separated as they are by an _ exceedingly 
thin strip of connective tissue, im which occur minute 
calcareous granules. In close proximity to the posterior 
extremity of the body, the transverse muscles become 
somewhat stronger, forming a sphincter round the anal 
opening. At the anterior extremity, they contribute in 
forming a sphincter round the mouth. Whether these 
transverse muscles uninterruptedly encircle the body on the 
inner surface of the integument, and thus constitute true 
annular muscles, or whether they are intersected by the long- 
itudinal muscles, we have as yet been unable to determine; 
the materials before us were far too scanty for arriving at 
a decision on so intricate a subject, the investigation of 
which must in itself be attended with very considerable 
difficulty; but, judging from the data our observations have 
supplied, we are prone to believe there is an intersection, 
such as occurs in Trochostoma, to which we called atten- 
tion when describing the transverse muscles in that genus. 
The longitudinal muscles are 5 in number — two on 
the back and three on the belly. They extend from the 
orifice of the mouth to the anal opening, are disconnected, 
rather thick, about 8”” broad, and webbed to the trans- 
verse muscles as well as to the corium by numerous fila- 
ments of connective tissue, fig. 3, a. At the posterior ex- 
tremity of the body, they diminish in thickness, and at the 
anterior, where they likewise assume a more slender ap- 
pearance; they protend to the under surface of the oral 
disk. being connected with it in the vicinity of the mouth. 
The muscular layer is covered by the peritoneum, con- 
sisting of connective tissue, in which are a few muscular 
fibres, numbers of scattered, exceedingly minute, oblong 
calcareous particles, and with a ciliated epithelial tunic on 
its inner surface. — me! 
In the skin of the body are numbers of calcareous 
corpuscles, occurring principally in two forms, — as slender © 
acuminate rods (spiculæ) and as elliptic plates. The spic- 
ule scattered, exhibiting at a few points 
only, in proximity to the suckers for instance, a closer 
arrangement. They are exceedingly minute, from 0.054" to 
0.0807" in length, and from 0.002” to 0.003” in breadth, 
and the greater part curvate, not unlike a horseshoe, figs. 
5, 5,5, some, however, almost straight, figs. 4,6,6. In the 
middle of each spicula occurs a small protuberance, and parts 
of both extremities are minutely serrated, figs. 5, 6, 7; but 
very few of these spiculæ branch, figs. 8. It is more especially 
the outer layer of the corium through which the spicule 
are distributed. a few only being met with in the inner. 
The elliptic corpuscles occur chiefly in the inner layer; 
some however are dispersed among the spiculæ in the outer. 
They are flat in appearance, and consist of two parts, one 
peripherie and uncoloured, which is the broadest, and one 
are rather 
1 Magazin for Naturvid. 24 Bind, pag. 232. Christiania 1878. 
